GRB 251125A
GCN Circular 42831
Subject
Fermi GRB 251125A: Global MASTER-Net observations report
Date
2025-11-25T01:15:21Z (5 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko,
G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 251125A ( Fermi GBM team, GCN 42830) errorbox 29 sec after notice time and 35 sec after trigger time at 2025-11-25 01:00:14 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 58 deg. The sun altitude is -35.2 deg.
MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 251125A errorbox 58 sec after notice time and 64 sec after trigger time at 2025-11-25 01:00:43 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 65 deg. The sun altitude is -25.5 deg.
The galactic latitude b = 44 deg., longitude l = 259 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3051146
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
40 | 2025-11-25 01:00:14 | MASTER-Kislovodsk | (10h 47m 41.84s , -02d 16m 18.0s) | C | 10 | 16.6 |
69 | 2025-11-25 01:00:43 | MASTER-SAAO | (10h 46m 14.24s , -02d 25m 57.0s) | C | 10 | 17.6 |
69 | 2025-11-25 01:00:43 | MASTER-SAAO | (10h 48m 05.24s , -02d 41m 35.6s) | C | 10 | 17.7 |
70 | 2025-11-25 01:00:44 | MASTER-Kislovodsk | (10h 47m 41.88s , -02d 16m 25.2s) | C | 10 | 16.7 |
103 | 2025-11-25 01:01:12 | MASTER-SAAO | (10h 46m 14.21s , -02d 25m 59.4s) | C | 20 | 18.1 |
103 | 2025-11-25 01:01:12 | MASTER-SAAO | (10h 48m 05.20s , -02d 41m 35.0s) | C | 20 | 18.5 |
106 | 2025-11-25 01:01:14 | MASTER-Kislovodsk | (10h 47m 41.94s , -02d 16m 40.7s) | C | 20 | 17.2 |
147 | 2025-11-25 01:01:51 | MASTER-SAAO | (10h 46m 14.28s , -02d 25m 58.7s) | C | 30 | 18.5 |
147 | 2025-11-25 01:01:51 | MASTER-SAAO | (10h 48m 05.23s , -02d 41m 33.9s) | C | 30 | 18.8 |
146 | 2025-11-25 01:01:54 | MASTER-Kislovodsk | (10h 47m 41.97s , -02d 16m 43.6s) | C | 20 | 17.2 |
181 | 2025-11-25 01:01:54 | MASTER-Kislovodsk | (10h 47m 41.96s , -02d 16m 43.7s) | C | 90 | 18.2 | Coadd
195 | 2025-11-25 01:02:38 | MASTER-Kislovodsk | (10h 47m 41.94s , -02d 16m 44.6s) | C | 30 | 17.5 |
201 | 2025-11-25 01:02:40 | MASTER-SAAO | (10h 46m 14.26s , -02d 25m 58.4s) | C | 40 | 18.8 |
201 | 2025-11-25 01:02:40 | MASTER-SAAO | (10h 48m 05.20s , -02d 41m 33.1s) | C | 40 | 18.9 |
250 | 2025-11-25 01:03:28 | MASTER-Kislovodsk | (10h 47m 41.92s , -02d 16m 45.1s) | C | 40 | 17.8 |
265 | 2025-11-25 01:03:39 | MASTER-SAAO | (10h 46m 14.24s , -02d 25m 58.5s) | C | 50 | 18.9 |
265 | 2025-11-25 01:03:39 | MASTER-SAAO | (10h 48m 05.17s , -02d 41m 32.9s) | C | 50 | 19.0 |
315 | 2025-11-25 01:04:28 | MASTER-Kislovodsk | (10h 47m 41.90s , -02d 16m 45.0s) | C | 50 | 17.8 |
315 | 2025-11-25 01:04:28 | MASTER-Kislovodsk | (10h 52m 01.99s , -02d 40m 47.8s) | C | 50 | 12.0 |
340 | 2025-11-25 01:04:48 | MASTER-SAAO | (10h 46m 14.20s , -02d 25m 58.8s) | C | 60 | 19.1 |
340 | 2025-11-25 01:04:48 | MASTER-SAAO | (10h 48m 05.12s , -02d 41m 32.9s) | C | 60 | 19.3 |
395 | 2025-11-25 01:05:38 | MASTER-Kislovodsk | (10h 47m 41.86s , -02d 16m 44.4s) | C | 70 | 18.1 |
480 | 2025-11-25 01:07:08 | MASTER-Kislovodsk | (10h 51m 53.78s , -02d 19m 53.0s) | C | 60 | 17.8 |
560 | 2025-11-25 01:08:28 | MASTER-Kislovodsk | (10h 51m 23.73s , -00d 26m 51.2s) | C | 60 | 18.0 |
639 | 2025-11-25 01:09:48 | MASTER-Kislovodsk | (10h 36m 38.70s , -02d 21m 11.9s) | C | 60 | 17.0 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html
GCN Circular 42830
Subject
GRB 251125A: Fermi GBM Final Real-time Localization
Date
2025-11-25T01:09:58Z (5 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 00:59:38 UT on 25 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251125A (trigger 785725183.783164 / 251125041).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 161.9, Dec = -7.6 (J2000 degrees, equivalent to J2000 10h 47m, -7d 35'), with a statistical uncertainty of 7.6 degrees.
The angle from the Fermi LAT boresight is 37.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125041/quicklook/glg_skymap_all_bn251125041.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125041/quicklook/glg_healpix_all_bn251125041.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125041/quicklook/glg_lc_medres34_bn251125041.gif